Institute for Cognitive Neuroscience, Department of Biopsychology, Ruhr-Universität Bochum, Germany.
Neuroimage. 2010 Apr 1;50(2):764-71. doi: 10.1016/j.neuroimage.2009.11.067. Epub 2009 Dec 3.
Response selection and control are supposed to reflect important basal ganglia functions. Recently, we showed that the dopaminergic system may be especially important for response selection in compatible, but not in incompatible stimulus-response (S-R) relations. Research indicates that the dopaminergic system is influenced by the serotonergic system, but little is known about the involvement of the serotonergic system in response selection. Analyzing event-related potentials (ERPs) in a sample of healthy probands (N=74), we show the 5-HT1A C(-1019)G polymorphism modulating response-related processes, as reflected in the N2 component, in compatible, but not incompatible, S-R relations. This modulation was a function of the number of -1019 G alleles. Decreasing numbers of -1019 G alleles were stepwise related to increases in the N2 on compatible trials and concomitant increases in response times. The functional effect of the 5-HT1A C(-1019)G polymorphism has previously been shown to be specific for serotonergic 1 A autoreceptors of serotonergic neurons in the dorsal raphe nucleus (DRN). Due to this close relation of genotype effects to neuroanatomically dissociable structures, the results suggest that DRN serotonin 1 A autoreceptors are important for compatible S-R relations, i.e., response selection, but not for incompatible S-R relations, i.e. response conflict or inhibition. The results extend previous findings on the dopaminergic system to the serotonergic system. The examined functions are precisely regulated on a neuronal level, since neurophysiological and behavioural effects are driven in an allele-dose fashion. Because of this, the results are of importance for future clinical applications.
反应选择和控制被认为反映了基底神经节的重要功能。最近，我们表明，多巴胺能系统可能对相容但不兼容的刺激-反应（S-R）关系中的反应选择特别重要。研究表明，多巴胺能系统受 5-羟色胺能系统的影响，但对 5-羟色胺能系统在反应选择中的参与知之甚少。在一组健康被试者（N=74）中分析事件相关电位（ERP），我们发现 5-HT1A C（-1019）G 多态性调节反应相关过程，如 N2 成分反映的那样，在相容但不兼容的 S-R 关系中。这种调制是 -1019 G 等位基因数量的函数。-1019 G 等位基因数量的减少与相容试验中 N2 的增加以及伴随的反应时间的增加呈逐步相关。5-HT1A C（-1019）G 多态性的功能效应以前被证明是特异性的，作用于背侧中缝核（DRN）中 5-羟色胺能神经元的 5-羟色胺 1A 自身受体。由于基因型效应与神经解剖学上可分离结构的密切关系，结果表明，DRN 5-羟色胺 1A 自身受体对相容 S-R 关系（即反应选择）很重要，但对不相容 S-R 关系（即反应冲突或抑制）不重要。这些结果将以前关于多巴胺能系统的发现扩展到 5-羟色胺能系统。所检查的功能在神经元水平上得到精确调节，因为神经生理和行为效应以等位基因剂量的方式驱动。由于这一点，结果对于未来的临床应用很重要。
